Autism has been characterized by deficits in communication and social skills, and restricted, repetitive, and stereotyped behavior patterns. Scientists from a variety of theoretical perspectives have sought to understand, explain and modify these deficits. For example, neuropsychological approaches have employed a variety of tests to examine how these impairments result from Executive Functioning (EF) deficits. Another approach, based on learning theory, has applied operant eonditioning research methods in an attempt to show that the primary deficits characteristic of autism are related to problems with Discriminative Control (DC). Specifically, this work has focused on the identification and remediation of problems related to stimulus overselectivity, the tendency to respond to certain features of complex stimuli to the exclusion of others. This line of research has been translated into behavioral teaching strategies, that when applied as an intensive educational program, increase intellectual functioning and decrease autistic behavior. Aside from heuristic value and clinical application, both EF and DC represent schema for understanding the basis of the behavioral features of autism and their associated deficits. Similarly, deficits in EF and DC (e.g., stimulus overselectivity) may be functions of more fundamental psychological processes related to deficits in contingency control. We propose here a series of experiments to investigate the extent to which the behavioral deficits of autism reflect excessive behavioral persistence, decreased sensitivity to ongoing contingencies, and decreased behavioral variation, and will employ operant methods used traditionally in the laboratory. The use of these operant learning tasks will permit the quantitative analysis of performances, precise identification of deficits, and analysis of the specificity of these deficits as a function of autism, relative to control subjects without autism and with mental retardation. In an attempt to understand how the operant constructs being examined in the current study are related to EF deficits, performance on operant tasks will be compared with neuropsychological tasks traditionally used to examine EF deficits in autism. Moreover, by including measures that reliably show deficits among individuals with autism (specifically, the Wisconsin Card Sorting Task and the Tower of Hanoi), performance differences on the operant tasks can be interpreted in the context of an established frame of reference. The proposed investigation can be used to set up future comparative research to contrast EF and operant approaches to the performance deficits displayed by individuals with autism.